ObjectDB Database Search

and sometimes we don't get the entity by query. Have you an idea what happens here?   btc_es BTC EmbeddedSystems

Queries are represented in JPA 2 by two interfaces - the old Query interface ... with an EntityManager (represented by em in the following code snippets), which serves as a factory ... which retrieves all the Country objects in the database is represented by both q1 and q2 . When building

|| NOT ! JPQL follows the SQL notation, while Java uses its own notation (which is also in use by JDOQL ... expressions are represented in criteria queries by Expression and descendant interfaces. For example, a boolean path (a field or a property) is represented by Path : Path isInUN = country

named queries instead of dynamic queries may improve code organization by separating the JPQL ... carefully to avoid collision (e.g. by using the unique entity name as a prefix). It makes sense to add ... at Runtime Named queries are represented at runtime by the same Query and TypedQuery interfaces

The following arithmetic operators are supported by JPA: 2 unary operators:   + (plus) and - (minus). 4 ... of the same type. The MOD Function The MOD function calculates the remainder of the division of one number by another, similar to the modulo operator ( % ) in Java (which is also supported by ObjectDB as

This chapter demonstrates basic ObjectDB and JPA concepts by introducing a simple example program ... that contains points in the plane. Each point is represented by an object with two int fields, x and y, that hold the point's x and y coordinates. The program demonstrates CRUD database operations by

ObjectDB server can manage different types of databases, including master databases, slave database ( by ... The configuration above demonstrates a situation in which the master database is managed by a server on localhost:6000 and the slave database is managed  by a server on localhost:6001 . In this case

grouped by the application, and which must be colocated in their mapping to a single database ... to create and remove persistent entity instances, to find entities by their primary key, and to query over entities. The set of entities that can be managed by a given EntityManager instance

As demonstrated in this forum thread , a mapped by collection field with lazy fetch mode is not initialized in results of a query that uses JOIN FETCH on that collection field (when enhancement is used). support Support   Build 2.4.1_06 fixes this issue (fields are now initialized

;      Every user is represented by a single element: The required username ... inherited by all the other user definitions but the master user itself cannot be used to connect ... . $user represents the user's username and if specified for the master ( "$default") it is interpreted by

of an entity class are detected by ObjectDB. New entity objects have to be stored in the new class ... again. Conversion of an entity object to the new schema is done on a field by field basis: For every field ... ) The automatic schema evolution mechanism, as described above, is based on matching fields by

) is that in JPA data is represented by classes and objects rather than by tables and records as in ... of the Java Persistence API (JPA). By interacting with ObjectDB using standard JPA

. The four relationship modes are represented by the following annotations: Unlike ORM JPA ... annotations are supported by ObjectDB for the inverse side of a bidirectional relationship (which is calculated by a query) : Details about all these annotations are provided in Chapter 2 of the ObjectDB manual.

In JPA a database connection is represented by the EntityManager interface. Therefore, in order ... by ObjectDB to be a database URL rather than a persistence unit name. The $objectdb variable represents the ObjectDB home directory ( by default - the directory in which ObjectDB is installed

, other schema changes are handled by ObjectDB automatically. Note: Extreme caution is required ... is changed from the original name, which is specified by the required name attribute, to the new name ... attribute is specified the class name is changed from the original name, which is specified by

collection after query execution (e.g. by results.get(0) ). To eliminate this routine operation JPA ... = (Long)query. getSingleResult (); An aggregate COUNT query always returns one result, by definition ... - the executeUpdate method returns the number of objects that have been updated or deleted by the query

This chapter introduced the basic principles of JPA using ObjectDB. You can go into details by ... your own ObjectDB/JPA projects simply by modifying this sample program. Reading the Next Chapters ... the picture by describing some tools and settings that are specific to ObjectDB:

We start by creating a new Eclipse Dynamic Web Project: Open the [New Project] dialog box, e.g. by ... as a new server by clicking the New Runtime... button . Follow the instructions and specify the path ... web project. Now, add ObjectDB support to the new Eclipse Project - by dragging the objectdb

The Guest entity objects will be stored in an ObjectDB database, which will be represented by ... created if not existing yet) when the web application starts, by instantiating ... down), by closing the  EntityManagerFactory . To register a ServletContextListener : Open the [New

The Guest entity objects will be stored in an ObjectDB database, which will be represented by ... created if not existing yet) when the web application starts, by instantiating an EntityManagerFactory . The database will be closed when the web application stops (or when the web server shuts down), by

In this final step we will add a simple table to the report: Open the [Insert Table] dialog box by ... ) layout. Set the column number to 2 , number of details to 1 , select the data set (e.g. Points by X ) in the third field and click OK . Fill the table with data by dragging the x and y columns from

You can now run the application by right clicking the Main.java file (in the [ Package Explorer ] window) and selecting Run As Java Application . The expected output in the Eclipse [Console] window ... by opening it in the ObjectDB Explorer : This is the end of the Eclipse JPA tutorial. Learn more about ObjectDB and JPA by reading the Manual .

You can run the application now by right clicking the Main node (in the [Projects] window ... 1,000 objects. You can view the content of the database file by opening it in the ObjectDB Explorer : This is the end of the tutorial. Learn more about ObjectDB and JPA by reading the Manual .

] dialog box by right clicking the Web Pages node (in the [Projects] window) and selecting New JSP ... a simple form for signing the guestbook, followed by a list of all the guests that have already signed (which are retrieved from the request's "guests" attribute that is set by the servlet in

We start by creating a new NetBeans Web Application Project: Open the [New Project] dialog box, e.g. by using File New Project... Select Java Web Web Application and click Next . Choose a Project ... : You may have to add Tomcat 6 as a new server by clicking the Add... button . Follow the instructions and specify

] dialog box by right clicking the WebContent node (in the [Package Explorer] window), selecting ... generates the guestbook page output, which contains a simple form for signing the guestbook, followed by ... " attribute that is set by the servlet in the previous step). The next step (and the last one in this tutorial) is running the web application .

application manages a basic guestbook page. Every visitor can sign the guestbook by filling a simple form. The visitors that have already signed are listed below the form: Persistence is managed by JPA. Every visitor that has signed the guestbook is represented by a Guest entity object

. The demo web application manages a basic guestbook page. Every visitor can sign the guestbook by ... is managed by JPA. Every visitor that has signed the guestbook is represented by a Guest entity object

] dialog box by right clicking the Web Pages node (in the [Projects] window) and selecting New JSP ... a simple form for signing the guestbook, followed by a list of all the guests that have already signed (which are retrieved from the request's "guests" attribute that is set by the servlet in

box by right clicking the guest package node (in the [Projects] window) and selecting New Servlet ... to generate the page output. Notice that operations on the database are carried on by the  GuestDao session bean, which is instantiated and injected by the application server into the 

. Every visitor can sign the guestbook by filling a simple form. The visitors that have already signed are listed below the form: Persistence is managed by JPA. Every visitor that has signed the guestbook is represented by a Guest entity object and all the Guest entity objects are stored in

the [New Entity Class] dialog box, e.g. by right clicking the project node (in the [Projects] window ... to the project (under Configuration Files). Open the persistence.xml file in a text editor ( by right clicking and selecting Edit or by double click and then moving to the Source or XML tab in

We start by creating a new Java EE dynamic web project in Eclipse: Open the [New Project] dialog box, e.g. by using File New Project... Select Web Dynamic Web Project and click Next . Choose ... runtime. Note: You may have to add GlassFish 3 as a new server by clicking the New Runtime... button

] dialog box by right clicking the WebContent node (in the [Package Explorer] window), selecting ... the guestbook, followed by a list of all the guests that have already signed (which are retrieved from the request's "guests" attribute that is set by the servlet in the previous step). The next step

the [New Java Class] dialog box, e.g. by right clicking the project node (in the [Package Explorer] window ... + ")"; } } The Guest entity class will represents guests in the database. We also need to configure JPA by setting a META-INF/persistence.xml file: Open the [New Folder] dialog box, e.g. by right clicking the project

In this step we will add a servlet to manage guestbook web requests: Open the [Create Servlet] dialog box by right clicking the guest package node (in the [Package Explorer] window), selecting  ... on the database are carried on by the GuestDao session bean, which is instantiated and injected by

can sign the guestbook by filling a simple form. The visitors that have already signed are listed below the form: Persistence is managed by JPA. Every visitor that has signed the guestbook is represented by a Guest entity object and all the Guest entity objects are stored in an ObjectDB database

] dialog box by right clicking the WEB-INF node under the Web Pages node (in the [Projects] window ... , which contains a simple form for signing the guestbook, followed by a list of all the guests that have already signed (which are retrieved from the request's guestDao attribute that is set by

manages a basic guestbook page. Every visitor can sign the guestbook by filling a simple form. The visitors that have already signed are listed below the form: Persistence is managed by JPA. Every visitor that has signed the guestbook is represented by a Guest JPA entity object and all the Guest

To store objects in an ObjectDB database using JPA we need to define an entity class: Open the [New Entity Class] dialog box, e.g. by right clicking the project node (in the [Projects] window ... a text editor ( by right clicking and selecting Edit or by double click and then moving to the XML

can sign the guestbook by filling a simple form. The visitors that have already signed are listed below the form: Persistence is managed by JPA. Every visitor that has signed the guestbook is represented by a  Guest entity object and all the  Guest entity objects are stored in an ObjectDB

] dialog box by right clicking WEB-INF under src/main/webapp (in the [Package Explorer] window ... the guestbook, followed by a list of all the guests that have already signed (which are retrieved from the request's  guestDao attribute that is set by the controller in the previous step

can sign the guestbook by filling a simple form. The visitors that have already signed are listed below the form: Persistence is managed by JPA. Every visitor that has signed the guestbook is represented by a  Guest entity object and all the  Guest entity objects are stored in an ObjectDB

a basic guestbook page. Every visitor can sign the guestbook by filling a simple form. The visitors that have already signed are listed below the form: Persistence is managed by JPA. Every visitor that has signed the guestbook is represented by a  Guest JPA entity object and all the  Guest

The  JPA Web Application tutorial provides step by step instructions on how to build a simple ... . Building a new application step by step is an effective way to learn - but if you prefer ... ) If  Maven is installed - extract the zip and run the application from the command line by

. This category includes members defined in the default fetch group in xml or annotations. Redefining the default fetch group via the API does not affect the members defined by this category. Using this category also sets the fetch-depth for the members in the default fetch group . Since: JDO 2.2

values should be retrieved. The fields in the current fetch group must be retrieved, and the implementation might retrieve more fields than the current fetch group . If the useFetchPlan parameter is false ... , all fields in the current fetch plan are fetched, and other fields might be fetched lazily by

should be retrieved. The fields in the current fetch group must be retrieved, and the implementation might retrieve more fields than the current fetch group . If the useFetchPlan parameter is false ... , all fields in the current fetch plan are fetched, and other fields might be fetched lazily by

should be retrieved. The fields in the current fetch group must be retrieved, and the implementation might retrieve more fields than the current fetch group . If the useFetchPlan parameter is false ... , all fields in the current fetch plan are fetched, and other fields might be fetched lazily by

technology by Sun Microsystems. The main purpose of this guide is to familiarise you with ObjectDB ... class is and which types are supported by JDO. Chapter 4 - JDO Metadata Shows how to define JDO ... you may want to extend your knowledge of JDO by reading the JDO specification or a book on JDO